1. Field of the Invention
The present invention relates to a susceptor and a vapor phase growth apparatus, and more particularly, to a susceptor permitting the manufacturing of an epitaxial wafer comprising an epitaxial layer of uniform thickness, and to a vapor phase growth apparatus comprising the susceptor.
The present invention further relates to a method of manufacturing an epitaxial wafer employing the above susceptor.
2. Discussion of the Background of the Invention
The reduction of crystal defects in semiconductors, particularly crystal defects on or near the surface, has been gaining importance in recent years with the high level of integration of semiconductor devices. Thus, the demand is increasing for epitaxial wafers obtained by vapor phase growth of epitaxial films of good crystallinity on the surfaces of substrate wafers.
An epitaxial wafer is normally manufactured by feeding a starting material gas onto the surface of a substrate wafer while the substrate wafer is being supported by a susceptor to induce vapor phase growth of an epitaxial layer. A susceptor having a counterbored groove receiving the wafer is generally employed. Such susceptor is disclosed in, for example, Japanese Unexamined Patent Publication (KOKAI) No. 2003-12397, which is expressly incorporated herein by reference in its entirety.
The use rate in the surface when manufacturing semiconductor devices from epitaxial wafers has tended to increase with the level of integration in recent years. However, when a conventional susceptor such as the susceptor described in Japanese Unexamined Patent Publication (KOKAI) No. 2003-12397 is employed to vapor phase grow an epitaxial film on a substrate wafer, depending on the orientation of the crystal axis, a phenomenon has tended to occur whereby the thickness along the perimeter portion of the epitaxial film has differed from the thickness at the center portion thereof. The perimeter portions of such epitaxial wafers cannot be used to fabricate devices, making it difficult to raise the use rate in the surface.